Weighing approximately one kilogram each, the 10-centimetre cube-shaped satellites are powered by solar panels and rechargeable batteries and make use of cameras, a spectrometer, ozone and CO2 sensors, a Geiger counter and temperature gauges. They also use a low-cost computer running Arduino, an open-source platform that allows for controlling the instruments aboard the satellite.

''There's been so much interest in them that they're basically booked solid,'' Mr Oxer said.

One proposed experiment is to measure sunspot activity and radiation levels to see if there is any correlation, Mr Oxer said. Another plans to listen for radio transmissions or radio stations that are over the horizon in order to detect meteors.

They are believed to be the first crowd-funded satellites to reach space and will soon be joined by several others, including the ARKYD, which Planetary Resources is behind - ''a space telescope for everyone'' - and the FUNcube, which both the Amateur Radio Satellite Foundation in the Netherlands and Britain are behind.